Article:Development of Ionic Electrical Thrust Technology

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The physics of the US stealth program

by Tim Harwood, M.A.

Originally written in 2004

In the last few years electric thrusters, commonly referred to as 'Lifters,' have achieved popularity as a home science project on the Internet. Advocates claim they are a significant technological breakthrough that promises anti-gravity anomalies and a possible new era of solid state electric flight. In fact this area of physics was thoroughly researched in the 1960s and then rolled into stealth projects in the early 1970s. The key point stealth engineers grasped was that radar invisibility was pointless, if a plane put out a huge conventional heat signature - electric thrust was the answer.

Electric Vacuum Pumps of the 1930s

Aside from the work of PowerPedia:Thomas Townsend Brown, which is sufficiently well known, I have decided to exclude it from the scope of this article. I have been able to trace the origins of ionic thrust technology back as far as 1935. Casual research surely goes back further, but this is the oldest documented evidence I can find of commercial grade development interest. Nikola Tesla definitely undertook experiments in this area likely starting sometime in the late 1890s leading to the development of the "OS:Beer glass thruster". He spoke of the invention, but kept the precise details enigmatic and unpatented. While many later researchers were keen to see the possibilities of solid state electrical thrust, C.W. Hansell who was studying this effect in the 1930s, apparently under funding from Radio Corporation of America, perceived it to be commercially useful as an electric vacuum pump, as recorded in US patent 2,022,465 (Figure 1).

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Problems with the mechanical vacuum pumps of the day included demanding manufacturing tolerances, difficult operation, and liability to component failure. As always, inventors seek to solve the specific engineering challenges of their time. As stated in the patent, Mr Hansell had realized a direct current discharge would have the result of manifesting a ' flow of electrons in one direction, and a flow of gas ions and molecules in the other direction .' This is illustrated in the patent as given in Figure 1.

We can deduce that the idea of an electric pump captured the imagination of researchers in the period, because further patents were issued, indicating interest was sufficient to merit further development funds. For example in 1939 Mr R.W. Reitherman was granted US patent 2,182,751 for his 'electronic pump.' He provides us with his an operating voltage of 15,000v, stepped up from a standard 110v input. He notes when the electrons collide with the molecules, positive ions are produced, resulting in an ionized gas that flows towards the anode.

Perhaps feeling some competition, Mr Hansell filed another patent published in 1942 numbered 2,282,401. It is remarkable to see in this 1942 patent, before even the work of Townsend Brown, such an advanced discussion of system variables. For example, in order to better direct the thrust of his system, the following optimization was derived:

: ' A magnetic field is so arranged in conjunction with the vacuum pump that the electron paths are brought closer together and lengthened out, which results in increasing the speed of the pumping action and increasing the final obtainable vacuum....... The application of a magnetic field gives many of the electrons a longer spiraled path and therefore the probability for collision with gas molecules is greatly increased. This causes an increase in ionization with a resultant increased pumping effect for a given value of cathode electron emission current .'

Electrostatic Precipitation of the 1940s

A further application of atmospheric particulate precipitation was suggested in a 1942 patent filed by W. H. Bennett. Devices continue to be sold using electrostatic process to precipitate dust and pollution from a variety of environments, both commercial and residential. To this extent, practical commercial technology based upon the ionic thrust effect, entered mass production many decades ago. One of the features of his research that Mr. Bennett likes to highlight with pride, is his development of ' diffuse discharge ,' which enables the air to be charged without ' arcing, sparking or streaming .' The keys to this are given in the patent:

1) The spacing between the emitting and collecting electrode

2) Conductivity of the emitting electrodes

3) Diameter of the tips of the emitting electrodes

4) Spacial distance between adjacent emitting electrodes

Thus we see that Mr. Bennett has further refined the art, and gone a long way towards addressing issues that had hindered commercialization of earlier iterations of the technology, such as burning out of the electrodes, and dangerous electrical sparking. The non sparking ' diffuse discharge ' concept pioneered in this patent is key to the operation of ionic thrust cells. The layout used by Mr Bennett is illustrated directly from the patent 2,295,152 in Figure 2.

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Ionic Wind Generating Duct of the 1950s

Further progress in the art is seen in 1956 with US patent 2,765,975 filed by Nils E Lindenblad, Princeton, again for Radio Corporation of America, over twenty years after the first ionic patents were filed. The patent describes a system for converting electric energy to kinetic. The advantages are stated to be solid state operation, without the need for moving parts as in the case of a mechanical fan. The thrust may also be directed, although commercial flight is not considered. The basic apparatus is illustrated in Figure 3.

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' A pipe or duct composed of alternate conductive and insulating sleeves. The sleeves may be cylindrical in cross section. A corona discharge device is positioned near the entrance to each conductive section of the duct. ....Either the discharge points or the conductive sleeves may be grounded. The propelling forces which are obtained in each section upon application of the device are thus made to be serially additive. The emerging ions are neutralized by means of polarized sections or members placed within and across the exist of the apparatus. The members just referred to in the nature of grids .'

Professional Aerospace Electrical Thrust Development in the 1960s

That an anti-gravity mania of sorts enveloped sections of the American aircraft industry in the 1960s, remains remembered in the lore of the industry. However, those researchers who have examined this and questioned what become of the research, have failed to inspect the patent records of the period, where precise technical details of the apparatus being developed and tested remain preserved for posterity, freely available to the sufficiently curious.

The anti gravity mania, was simply a continuation of ionic thrust experiments, dating back to the 30s, but with much higher levels of commercial interest and funding. One of the interesting points about US patent 3,071,705 by Coleman et al, is that it was filed on behalf of Grunman Aircraft Engineering Corporation. A well known American defense contractor. It documented a genuine attempt at developing practical apparatus for generating atmospheric electrical thrust. The second paragraph of the patent provides a masterful summary of Lifters physics, that I can do no better than reproduce:

' If an electrically charged conducting service has a relatively sharp point, a large part of the charge will concentrate in the neighborhood of the point, thus producing a high electrostatic stress in the air surrounding the point. Free electrons present in this region of air will be accelerated so strongly by the electrostatic force that by collision with neutral gas molecules they will strip or knock loose other electrons from these molecules. Thus, electron positive ion pairs will be created and the cumulative collision process known as the corona will result. Further, if the pointed conductor is positively charged, the positive ions present in the corona discharge will move away from the point because of mutual electrostatic repulsion, while the negative electrons will be attracted to the conductor. Neutral molecules will be struck by the repelled positive ions and momentum will be transferred from the ions to to the air mass in the vicinity of the point, thereby generating a flow of air. This flow of air, or so called electric wind, will be in directions radially outward from the point of the positively charged conductor and therefore of little or no use as propulsion means. In order to provide a useful and efficient device, the flow of air must be concentrated in one direction .'

The principals of the underlying physics of the system, are implemented in the apparatus shown in Figure 4. Some may consider the layout has similarities to Mark S. Tecson's 'Vortex Lifter.' The sharp discharge point is intended to provide a concentration of charge, an intended direction of air flow is given by the physical layout of the apparatus, a shaped magnetic field around the discharge point provided by the doughnut ring, further helps confine and direct the ionic air flow, and a target conducting surface, provides both an end point for the lines of magnetic force, and a target for the ionic wind. The design integrates in part, consideration of the fluid dynamics of the ionic air flow, showing an advanced grasp of both theoretical physics, and practical design implementation.

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But possibly the most remarkable electrical thrust patent from the period, is that filed by G.E. Hagen in 1964, on behalf of the Electronatom Corporation. I would encourage anyone who can spare the time to read this patent in full. It explicitly states it relates to ' a novel heavier than air craft which is propelled through the use of an electric discharge .' The apparatus described consists of a charged wire with ' fabric strips ' to funnel the air downwards, a collecting grid beneath charged to 15,000v, which as illustrated in Figure 5, may be arranged in layers, beneath which may be slung a gondola, within which one might hypothetically place a mouse for small scale lab experiments, or on a larger scale, a human being. The patent seems more or less identical, to the so called “Lifters” devices found on the Internet.

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One of the interesting points made in the patent, is that a larger volume of air moving at slower speeds, will have a higher efficiency than a smaller volume at higher speeds. Also of note, ' as the size is increased, the voltage may be advantageously increased with a resulting gain in lifting force, but without a corresponding increase in power, since the losses for a given ion current remain approximately the same .' Furthermore, ' the antenna current is preferably made as low as possible and maximum voltages are used to provide maximum efficiency. The low current is accompanied by a reduced corona discharge which was readily visible in a darkened room on some of the earlier designs .'

It is also noted that higher air flow speeds result in more violent collisions between the electrons and the air molecules, resulting in the formation of undesirable chemical compounds, and secondary ionization, which results in thrust in an opposite direction to that intended. It is noted ' aluminum strips with the edges bent downwardly reduce the secondary ionization that takes place at sharp edges .' The basic apparatus is illustrated in Figure 6.

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The Hagen patent is relatively modest about the actual usefulness of the physics, but offers the following words on possible practical applications:

' Maximum practical horizontal speed is expected to be limited to speeds of the order of about 200 to 250 miles per hour. At such speeds, the lift may be obtained principally by aerodynamic means and the ionic discharge system may then be used primarily as a forward propulsive system....... Flying craft covering a horizontal area of several thousand square feet and containing their own power supplies will be particularly well adapted for industrial and military applications requiring hovering devices at altitudes up to at least 10,000 to 20,000 feet, such as for example, offshore radar and weather stations, oil drilling rigs and the like. In view of the extremely low amount of power and maintenance required for the craft to remain aloft, my improved craft may also be economically used for relatively slow commercial travel and for various other applications .'

Research of Alexander de Seversky as per US Patent 3,130,945

But of all the old electrical thrust researchers, perhaps the best known is the colorful Major Seversky, due in part to his article in Popular Mechanics August 1964. His patent reveals some fascinating details of the actual research being conducted in this period and specifically states:

' An actual embodiment..... lifted itself into a self sustaining flight had a collecting grid surface area of approximately 150 square inches and the space between the collecting grid and the emitting wires was approximately 2 inches. With a craft having for foregoing dimensions, 0.5 ma was sufficient to make the craft more than self sustaining. The total weight of the structure was approximately 5 grams. Other craft having the space between the collecting grid and emitting wires of 5 inches have been successfully flown. Such craft requires voltages of the order of 50 to 60 kV. Where the grid area is about 7 or 8 square feet, current of the order of 2 ma exist .'

In other words the patent does not represent theory, but actual experiments. This is demonstrated by the fine grasp of detail, as once again we find it stated ' a considerable improvement in lifting force was achieved when the frame members and cut ends of the grid wires were covered with an aluminum foil .' The research was unquestionably advanced. Seversky had clearly mastered in a practical engineering sense, a degree of control over his lifting grid.

' When this voltage exceeds a certain level yet remains less than that which causes arcing, the craft will rise. The effect of potentiometers A,B, C, and D is to controllably reduce the voltage between the emitting wires and any one or two specific grid sections to thereby reduce or subtract from the effectiveness of that portion of the craft in producing its lifting force. This then causes the craft to tilt downwardly in the direction of whichever of the grid sections has the reduced voltage .'

The patent abounds with optimization suggestions, including hollow emitter wires, that while while not necessarily boosting efficiency, offered a practical reduction in material costs, anticipating possible mass production.

' The lifting capability of the craft was found to increase as the diameter of the grid wires is increased. Crafts were tested with wire diameter of 2,5,8 and 12 mils for the collecting grid. Wire wire diameters of 8 mils or more, the current requirement to provide the same total lifting force shows a detectable decrease thereby indicating a higher efficiency. Hollow tubular conductors having an outer diameter of one-quarter inch also give substantially the same lift force and efficiency as the 8 and 12 mil diameter wires .'

The Popular Science article gives further details of the research in progress, and reveals one way to significantly improve efficiency is to ' pulse the power in short high energy bursts rather than apply steady voltage .' It is stated ' round models in the form of a flying saucer will be the most easily maneuverable ,' and altitudes of up to 300,000 feet are envisaged, as opposed to 20,000 for helicopters. Somewhat intriguingly, Seversky promises a model with a self contained power supply ' perhaps by the end of the year,' based upon an onboard turbine generator.

Quasi Coronoa Aerodynamic Vehicle (3,464,207 - 1969)

This final patent contains an overview of the limitations of the ionic thrust effect manifested in the aforementioned apparatus, and also proposes possible solutions. It is noted for commercial applications ' the required thrust is considerable and is not achievable by this prior art ' unless prohibitively large emitter arrays are employed.

Researchers of the period considered the obvious answer to this problem to be an increase in the input voltage of the apparatus, and scale of ionization cells, because the aerodynamic pressure gradient was proportional to the square of the input voltage (field strength). However, the complete electric atmospheric breakdown value for continuous current is stated at about 30 kV / cm, and it is claimed this places a practical limit on the extent to which the input voltage could be increased, without the device forming a short circuit over air.

The health side effects of secondary ionization are also stated, which also tend to worsen with voltage. Namely ozone and toxic oxides of nitrogen are produced. It is noted ' ozone in concentrations of 8 parts per million, within 5 to 10 minutes produces as many chromosome breakages as 200 roentgen dose of x-rays .' This is aside from the inherent danger presented by high voltage parts of electrocution, and the problems excessive atmospheric moisture can cause, by altering the electric properties of the cell.

And finally, practical difficulties of consistent control once the vehicle is in motion are mentioned, for example ' when using a normal D.C. Corona electric wind device the generated pressure gradient increases asymptotically with the velocity of the vehicle. This asymptotic increase may cause instability of the pressure gradient leading to unreliable operation of the vehicle .'

However, by 1966 when this patent was originally filed, all these issues were widely known and understood, and resolutions had been formulated. It was proposed the problem of insufficient thrust could be tackled as follows:

' To significantly improve the amount of energy or power which can be driven into ionized gas discharge in air at atmospheric conditions and thus form a quasi-corona, it is necessary at least, to apply to asymmetric electrodes as high a voltage as possible for as brief a period as possible before the accumulative effects of these parameters initiate spark streamer in the quasi-corona discharge and so waste the input power or energy .'

The patent indicates a practical translation of these principals, includes a pulse generator than can handle input pulses as low as one nano second, input voltages at up to 150 kV, delivered at a frequency of up to 10 kHz, and a rise and fall time for the switch of no more than one third of the pulse period. It is further stated with such specialized pulse control apparatus, compared to a standard DC input, a resultant ten fold increase in the electric field strength can be obtained, and an impressive 25 fold increase in aerodynamic pressure, otherwise known as resultant thrust, utterly transforming the delivered performance of ionic cells. Thus larger cells, with ultra short on times below the time required to ionize a conducting path across the cell, for voltages in excess of 150kV, is the secret of commercial development of the effect, and this was clearly known by American defense contractors by the end of the 1960s, at the height of the so called aerospace electric anti-gravity mania.

Applications - Sub Sonic Stealth

An interesting point of speculation is why the patent trail dries up in the early 1970s, just as it appears they were finally starting to resolve the engineering problems they had initially encountered. Given the stated interest of Grunman corporation, among others, it is hard to believe so much time, effort, and money, could have been spent on something for no practical result.

It may be coincidence, but this was about the time when preliminary designs for the stealth fighter concept (Figure 7) were being evaluated. When trying to make an aircraft hard to detect, not only must the radar signature be considered, but also all other possible sources of detection, including infrared heat. Electric thrust cruise capability would deal with the heat threat vulnerability.

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It is a reasonable deduction that in seeking to minimize the infrared signature of the stealth fighter, electrical thrust technology was further developed in secret beyond what is given in the patents discussed, and used to augment the thrust provided by the jet engines, allowing them to be throttled back to the point where the heat emissions are minimized. On March 9, 1992, "Aviation Week and Space Technology" disclosed that the later B-2 stealth bomber, electrostatically charges its exhaust stream and the leading edges of its wing-like body, apparently validating this hypothesis.

Given the effect is optimized at higher voltages, a larger scale, and lower speeds, this sub sonic application for the technology makes good engineering sense. The hybrid drive is quite straightforward in operation, and minimizes duplication of components. Once in flight, the turbine shafts are electrically loaded and generate the high voltage output required to power the electric thrust drive. Since electrical drive is more efficient, the planes have an extended range for a given amount of fuel compared to conventional flight mode - another strong advantage for a plane typically deployed as an inter continental bomber.

It is also interesting to speculate, if stealth planes have a secondary electrical thrust system to augment the power output of the jet engines, they might have unusually high ozone emissions, or other by products of ionization, that could be detected by adapted missile warheads. Could either high voltage or chemical byproducts be the optimal way to detect and destroy American stealth aircraft? The Russians certainly seem confident they have missiles than can deal with "stealth."

Advanced Configurations

This article covers only the patent history of the development of the effect. Further optimization is possible, and no doubt has been undertaken in classified laboratories. At a simple level, the fluid dynamics of the entire craft should be considered, with air intake into the cell optimized, reducing chances of secondary ionization. Re-cycling the bow wake into the emitters also offers benefits. This is especially true as voltage is ramped into the hundreds of Kv, where the field effect increases relative to the electrostatic effect, and travel by field manipulation rather than action-reaction mass expulsion, can start to become considered. The patents do specifically state that ionisation alone is not sufficient to explain the delivered thrust on 150Kv configurations.

Summary

The patent archives provide a remarkable insight into the electrical thrust research that was undertaken by large American aerospace concerns in the 1960s. Even a casual perusal of the old patents, provides an absolute wealth of information, and some very acute insights into the underlying physics of these systems. It is clear that as research moved towards the field based side of the effect, with ramped voltages, and ultra short rise times, further patents stopped being filed, and the research was progressed under a classified basis.

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Appendix

RQ-170 Sentinel drone appears to be a mini version of the B2 tech, and is the sort of project that could be done by a University physics dept, once one has the understanding the length of the wing / body is the ionic cell. It would run on much lower voltages than the B2. Maybe somewhere around the million volt mark.

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X-47B is another drone plane using the same technology - quite old at this point.

Comments

About Tim Harwood

Tim has followed developments in energy research since the cold fusion claims of the early 1990s. For a period in 2001-2004 he ran the Adamsmotor Egroup. The basis for the group work was Tim's Directory:CDmotor, and OS:CD Motor, which while designed independently of Robert Adams, nonetheless appeared to mimic some of the claimed exotic performance characteristics, while being low cost ($50).

As a spin off, the Egroup also developed the Directory:PODcore experiment ($20). This was based upon Tim's novel theory that the Adams motor manifested the coupling of a time negative flux vector to a conventional current flow, causing a thermoelectric voltage gain, as well as doubling the rate of change of magnetic flux, halving current draw, due to the simultaneous presence of two time vectors.

This evolved into a variety of experiments using coils ($1) to pulse charge capacitors, and distribute the load via 'inverted' circuits. Reductions in current draw of 50% were typically reported with load types of small DC electric motors. Tom Bearden publically endorsed the work 12 months after it was originally published.

This ionic thrust article was written at the end of this period of research, as a further demonstration of the passion and natural affinity Tim has for high technology, and excellence in design. He has also proposed two new OS projects alongside the release of this new ionic thrust article, OS:Beer glass thruster, OS:CD magnetic ramp.

References

Major De Seversky's Ion Propelled Aircraft, Hans Fantel, Popular Mechanics, August 1964

A person who is demoralized is unable to assess true information. The facts tell nothing to him. Even if I shower him with information, with authentic proof, with documents, with pictures -Yuri Alexandrovich Bezmenov. KGB cold war defector.